Association of PD-L1 overexpression with activating EGFR mutations in surgically resected nonsmall-cell lung cancer

BACKGROUND

Recent clinical trials have shown that immune-checkpoint blockade yields a clinical response in a subset of individuals with advanced nonsmall-cell lung cancer (NSCLC). We examined whether the expression of programmed death-ligand 1 (PD-L1) is related to clinicopathologic or prognostic factors in patients with surgically resected NSCLC.

PATIENTS AND METHODS

The expression of PD-L1 was evaluated by immunohistochemical analysis in 164 specimens of surgically resected NSCLC. Cell surface expression of PD-L1 in NSCLC cell lines was quantified by flow cytometry.

RESULTS

Expression of PD-L1 in tumor specimens was significantly higher for women than for men, for never smokers than for smokers, and for patients with adenocarcinoma than for those with squamous cell carcinoma. Multivariate analysis revealed that the presence of epidermal growth factor receptor gene (EGFR) mutations and adenocarcinoma histology were significantly associated with increased PD-L1 expression in a manner independent of other factors. Cell surface expression of PD-L1 was also significantly higher in NSCLC cell lines positive for activating EGFR mutations than in those with wild-type EGFR. The EGFR inhibitor erlotinib downregulated PD-L1 expression in the former cell lines but not in the latter, suggesting that PD-L1 expression is increased by EGFR signaling conferred by activating EGFR mutations. A high level of PD-L1 expression in resected tumor tissue was associated with a significantly shorter overall survival for NSCLC patients.

CONCLUSIONS

High expression of PD-L1 was associated with the presence of EGFR mutations in surgically resected NSCLC and was an independent negative prognostic factor for this disease.

Weekly administration of paclitaxel and carboplatin with concurrent thoracic radiation in previously untreated elderly patients with locally advanced non-small-cell lung cancer: A case series of 20 patients

Elderly patients with stage III non-small-cell lung cancer (NSCLC) are frequently underrepresented in clinical trials that evaluate chemoradiotherapy, due to their poor functional status, coexisting illnesses and limited life expectancy. The Japan Clinical Oncology Group 0301 trial (JCOG0301) was the first study to demonstrate that thoracic radiation therapy (TRT) with daily low-dose carboplatin may improve the outcome of elderly patients with stage III NSCLC. However, the efficacy and safety profiles of chemoradiotherapy, including platinum doublets, have not been clearly determined in this patient population. We retrospectively assessed the efficacy and toxicity of weekly paclitaxel in combination with carboplatin and concurrent TRT in patients aged ≥75 years with previously untreated locally advanced NSCLC. Between February, 2004 and July, 2013, we collected the data of 20 patients treated with weekly paclitaxel and carboplatin for 6 weeks and concurrent TRT. The objective response rate was 90%, the disease control rate was 95%, the median progression-free survival was 8.63 months [95% confidence interval (CI): 5.7-16.7] and the median overall survival (OS) was 16.1 months (95% CI: 10.7-41.6). There were no grade 4 hematological or non-hematological toxicities and no reported treatment-related deaths. Therefore, platinum doublet therapy in combination with TRT did not provide a clinically significant survival benefit in our population of elderly patients with locally advanced NSCLC. However, the present study demonstrated the good feasibility and safety of this regimen. Further prospective clinical trials are required to evaluate the efficacy and safety of platinum doublet with TRT in elderly patients.

Bevacizumab for critical brain metastases in a patient with pulmonary pleomorphic carcinoma

Bevacizumab was initially contraindicated in patients with brain metastases, but several reports have shown the efficacy and safety of bevacizumab for brain metastases. We herein report the case of a patient with pulmonary pleomorphic carcinoma for which bevacizumab plus weekly paclitaxel following whole-brain radiotherapy (WBRT) was effectively and safely administered for critical and refractory brain metastases. Although the 50-year-old male patient received WBRT with anti-edema therapies for progressive brain metastases, his clinical symptoms deteriorated rapidly. After the completion of WBRT, we administered bevacizumab plus weekly paclitaxel, and his neurological symptoms improved dramatically. Brain magnetic resonance imaging demonstrated a marked response by the brain metastases and improved brain edema. This case suggested both synergism between WBRT and bevacizumab, and an anti-edema effect of bevacizumab. Bevacizumab may be therefore a potent therapeutic option for patients with refractory brain metastases.

A phase I/II trial of irinotecan plus amrubicin supported with G-CSF for extended small-cell lung cancer

OBJECTIVE

This study reports the findings of a Phase I/II, cohort, dose-escalation trial of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor. This study aimed to determine the dose-limiting toxicity of the combination and to define the maximum-tolerated dose, as a recommended dose for Phase II trials. We also sought to obtain preliminary data on the efficacy of this combination as a frontline therapy for extensive-disease small-cell lung cancer.

METHODS

We included 23 chemo-naïve patients with extensive-disease small-cell lung cancer in the trial. The amrubicin dose was escalated from 35 to 40 mg/m(2) (Levels 1 and 2, respectively) to determine the dose-limiting toxicity, with an unchanged dose of irinotecan at 50 mg/m(2).

RESULTS

Of nine patients, three experienced dose-limiting toxicities at Level 1 of prolonged Grade 4 neutropenia, Grade 3 febrile neutropenia and Grade 3 febrile neutropenia with Grade 3 diarrhea. At Level 2, two patients experienced dose-limiting toxicities of Grade 4 neutropenia and Grade 3 neutropenia with Grade 4 diarrhea. The maximum-tolerated doses and recommended doses for amrubicin and irinotecan were therefore determined to be 35 and 50 mg/m(2), respectively. The Level 1 trial was then expanded to 21 patients, 14 (70%) of whom showed partial responses to the recommended dose. The median progression-free and overall survival times were 6.37 and 15.21 months, respectively.

CONCLUSIONS

The combination of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor produced a potent effect in chemo-naïve extensive-disease small-cell lung cancer patients. The use of biomarkers for this regimen may identify patients who are likely to suffer from treatment-ending severe adverse effects.

Long-term outcomes of dynamic conformal arc irradiation combined with neoadjuvant hormonal therapy in Japanese patients with T1c-T2N0M0 prostate cancer: case series study

OBJECTIVE

There are few reports of the outcomes of external beam radiotherapy in Asian males with localized prostate cancer. The aim of this study is to evaluate the long-term outcomes of external beam irradiation using three-dimensional two-dynamic conformal arc therapy, combined with neoadjuvant hormonal therapy, in patients with T1c-T2N0M0 prostate cancer.

METHODS

Between March 2003 and August 2007, 150 Japanese patients with T1c-T2N0M0 prostate cancer were definitively treated with three-dimensional two-dynamic conformal arc therapy. The median age, pretreatment prostate-specific antigen values and neoadjuvant hormonal therapy period were 73 years, 9.4 ng/ml and 6 months, respectively. In principle, 74 Gy was delivered to the planning target volume, although the total dose was reduced to 70 Gy in patients with unfavorable risk factors, such as severe diabetes mellitus or anticoagulant therapy. No adjuvant hormonal therapy was given to any patient. Salvage hormonal therapy was started when the prostate-specific antigen value exceeded 4 ng/ml in a monotonically increasing manner.

RESULTS

The median follow-up period was 79 months. Salvage hormonal therapy was initiated in 10 patients and the median prostate-specific antigen value at the initiation was 4.7 ng/ml. The 5-year Kaplan-Meier estimates of the biochemical relapse-free survival rate, the salvage hormonal therapy -free rate and the overall survival rate were 83.3% (95% confidence interval = 77.1-89.6%), 94.3% (95% confidence interval = 90.4-98.1%) and 96.3% (95% confidence interval = 93.1-99.5%), respectively. The 5-year cumulative incidence rates of developing more than Grade 2 late rectal and urinary toxicities were 5.5 and 2.9%, respectively.

CONCLUSIONS

Three-dimensional two-dynamic conformal arc therapy, with up to 74 Gy, in patients with T1c-T2N0M0 prostate cancer with neoadjuvant hormonal therapy was well tolerated and achieved good biochemical control and survival outcomes.

The relationship between aryl hydrocarbon hydroxylase activity and DNA adducts measured by (32)P-postlabelling assay in lymphocytes of lung cancer patients

We have investigated the correlation between DNA adduct levels and aryl hydrocarbon hydroxylase (AHH) activity in peripheral lymphocyte samples obtained from 42 lung cancer patients. DNA adducts and AHH activity were determined by the (32)P-postlabelling technique and the fluorometric method, respectively. The mean +/- SD of DNA adduct level was 0.88 +/- 0.37 (ranged from 0.22 to 1.90) per 10(8) nucleotides. The geometric means of non-induced and 3-methylcholanthrene (MC)-induced AHH activity, as well as AHH inducibility (MC-induced AHH activity/non-induced AHH activity) were 0.029, 0.228 pmol min(-1) 10(-6) cells, and 7.776, respectively. There was no statistically significant correlation between DNA adduct levels and non-induced or MC-induced AHH activity. A tendency of positive correlation was found between DNA adduct levels and AHH inducibility for the all subjects (n = 42, r = 0.25, p = 0.11). Such a positive correlation reached statistical significance in the subjects with squamous cell carcinoma (n = 13, r = 0.70, p < 0.01). In addition, similar correlation of DNA adducts with AHH inducibility was also observed in the GSTM1 present genotype (n = 17, r = 0.44, p = 0.07) and GSTP1-AA genotype (n = 29, r = 0.37, p = 0.05) individuals. These findings suggest that DNA adduct levels are mediated by CYP1A1 enzyme, and AHH inducibility may be a more relevant indicator than specific AHH activity for explaining the variation of DNA adduct levels in lymphocytes.

Molecular epidemiology of canine GM1 gangliosidosis in the Shiba Inu breed in Japan: relationship between regional prevalence and carrier frequency

BACKGROUND

Canine GM1 gangliosidosis is a fatal disease in the Shiba Inu breed, which is one of the most popular traditional breeds in Japan and is maintained as a standard breed in many countries. Therefore, it is important to control and reduce the prevalence of GM1 gangliosidosis for maintaining the quality of this breed and to ensure supply of healthy dogs to prospective breeders and owners. This molecular epidemiological survey was performed to formulate an effective strategy for the control and prevention of this disease.

RESULTS

The survey was carried out among 590 clinically unaffected Shiba Inu dogs from the 8 districts of Japan, and a genotyping test was used to determine nation-wide and regional carrier frequencies. The number and native district of affected dogs identified in 16 years from 1997 to June 2013 were also surveyed retrospectively. Of the 590 dogs examined, 6 dogs (1.02%, 6/590) were carriers: 3 dogs (2.27%, 3/132) from the Kinki district and the other 3 dogs from the Hokkaido, Kanto, and Shikoku districts. The retrospective survey revealed 23 affected dogs, among which, 19 dogs (82.6%) were born within the last 7 years. Of the 23 affected dogs, 12 dogs (52.2%) were from the Kinki district. Pedigree analysis demonstrated that all the affected dogs and carriers with the pedigree information have a close blood relationship.

CONCLUSIONS

Our results showed that the current carrier frequency for GM1 gangliosidosis is on the average 1.02% in Japan and rather high in the Kinki district, which may be related to the high prevalence observed over the past 16 years in this region. This observation suggests that carrier dogs are distributed all over Japan; however, kennels in the Kinki district may face an increased risk of GM1 gangliosidosis. Therefore, for effective control and prevention of this disease, it is necessary to examine as many breeding dogs as possible from all regions of Japan, especially from kennels located in areas with high prevalence and carrier frequency.

Electronic phase transition and an anomalous ordered phase in Ba2Ti13O22 with 3d1 ions on a triangle-based lattice

We found that Ba(2)Ti(13)O(22) with Ti(3+) (3d(1)) ions on a triangle-based lattice exhibits a phase transition at T(c)~200 K, below which the increase of electrical resistivity and decrease of magnetic susceptibility were observed. Transmission electron microscopy and optical reflectivity measurements indicate that the low-temperature phase of the present compound shares characteristics in common with a charge-density-wave state with remnant carriers, although a commensurate wave vector of the modulation and a linear temperature dependence of the magnetic susceptibility below T(c) suggest an exotic ordered state.

Feasibility evaluation of a new irradiation technique: three-dimensional unicursal irradiation with the Vero4DRT (MHI-TM2000)

The Vero4DRT (MHI-TM2000) is a newly designed unique image-guided radiotherapy system consisting of an O-ring gantry. This system can realize a new irradiation technique in which both the gantry head and O-ring continuously and simultaneously rotate around the inner circumference of the O-ring and the vertical axis of the O-ring, respectively, during irradiation. This technique creates three-dimensional (3D) rotational dynamic conformal arc irradiation, which we term '3D unicursal irradiation'. The aim of this study was to present the concept and to estimate feasibility and potential advantages of the new irradiation technique. Collision maps were developed for the technique and a 3D unicursal plan was experimentally created in reference to the collision map for a pancreatic cancer case. Thereafter, dosimetric comparisons among the 3D unicursal, a two-dimensionally rotational dynamic conformal arc irradiation (2D-DCART), and an intensity-modulated radiation therapy (IMRT) plan were conducted. Dose volume data of the 3D unicursal plan were comparable or improved compared to those of the 2D-DCART and IMRT plans with respect to both the target and the organs at risk. The expected monitor unit (MU) number for the 3D unicursal plan was only 7% higher and 22.1% lower than the MUs for the 2D-DCART plan and IMRT plan, respectively. It is expected that the 3D unicursal irradiation technique has potential advantages in both treatment time and dose distribution, which should be validated under various conditions with a future version of the Vero4DRT fully implemented the function.

Risk factors predicting the outcome of salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy

OBJECTIVES

Salvage radiotherapy is the only curative treatment for patients with prostate cancer showing biochemical progression after radical prostatectomy. In this study, we evaluated the clinicopathological parameters that influence the outcome of salvage radiotherapy.

METHODS

Medical records of 49 patients who underwent salvage radiotherapy after radical prostatectomy from 1997 to 2008 at the Graduate School of Medicine, Kyoto University, were retrospectively reviewed. Radiotherapy was carried out with 66 Gy on the prostatic bed.

RESULTS

Biochemical progression-free survival after salvage radiotherapy at 2, 5 and 7 years was 51.0%, 42.2% and 42.2%, respectively. Significant parameters predicting biochemical progression after salvage radiotherapy by Cox regression analysis were prostatectomy Gleason score sum ≥ 8 (hazard ratio 0.08; 95% confidence interval 0.03-0.22; P=0.001), prostate-specific antigen nadir after radical prostatectomy ≥ 0.04 ng/mL (hazard ratio 0.30; 95% confidence interval 0.13-0.69; P=0.005) and negative surgical margin (hazard ratio 0.28; 95% confidence interval 0.12-0.70; P=0.006). When the patients were subgrouped by these risk factors, the 5-year progression-free survival rates after salvage radiotherapy were 77.8%, 50.0% and 6.7% in patients with 0, 1 and ≥ 2 predictors, respectively.

CONCLUSION

In order to discriminate favorable candidates for salvage radiotherapy, Gleason score of prostatectomy, prostate-specific antigen nadir after prostatectomy and positive surgical margin represent independent predictors. Thus, progression-free survival might be more precisely predicted according to the presence/absence of these risk factors. The significance of this risk classification should be confirmed by large prospective studies.

The effect of platelet-rich plasma on the regenerative therapy of muscle derived stem cells for articular cartilage repair

OBJECTIVE

Platelet-rich plasma (PRP) is reported to promote collagen synthesis and cell proliferation as well as enhance cartilage repair. Our previous study revealed that the intracapsular injection of muscle derived stem cells (MDSCs) expressing bone morphogenetic protein 4 (BMP-4) combined with soluble Flt-1 (sFlt1) was effective for repairing articular cartilage (AC) after osteoarthritis (OA) induction. The current study was undertaken to investigate whether PRP could further enhance the therapeutic effect of MDSC therapy for the OA treatment.

METHODS

MDSCs expressing BMP-4 and sFlt1 were mixed with PRP and injected into the knees of immunodeficient rats with chemically induced OA. Histological assessments were performed 4 and 12 weeks after cell transplantation. Moreover, to elucidate the repair mechanisms, we performed in vitro assays to assess cell proliferation, adhesion, migration and mixed pellet co-culture of MDSCs and OA chondrocytes.

RESULTS

The addition of PRP to MDSCs expressing BMP-4 and sFlt1 significantly improved AC repair histologically at week 4 compared to MDSCs expressing BMP-4 and sFlt1 alone. Higher numbers of cells producing type II collagen and lower levels of chondrocyte apoptosis were observed by MDSCs expressing BMP-4 and sFlt1 and mixed with PRP. In the in vitro experiments, the addition of PRP promoted proliferation, adhesion and migration of the MDSCs. During chondrogenic pellet culture, PRP tended to increase the number of type II collagen producing cells and in contrast to the in vivo data, it increased cell apoptosis.

CONCLUSIONS

Our findings indicate that PRP can promote the therapeutic potential of MDSCs expressing BMP-4 and sFlt1 for AC repair (4 weeks post-treatment) by promoting collagen synthesis, suppressing chondrocyte apoptosis and finally by enhancing the integration of the transplanted cells in the repair process.

Positional accuracy of novel x-ray-image-based dynamic tumor-tracking irradiation using a gimbaled MV x-ray head of a Vero4DRT (MHI-TM2000)

PURPOSE

To verify the positional accuracy of a novel x-ray-image-based dynamic tumor-tracking (DTT) irradiation technique using the gimbaled MV x-ray head of a Vero4DRT (MHI-TM2000).

METHODS

Verification of the x-ray-image-based DTT was performed using three components: a three-dimensional moving phantom with a steel ball target, a laser displacement gauge, and an orthogonal kV x-ray imaging subsystem with a gimbaled MV x-ray head and the system controller of the Vero4DRT. The moving phantom was driven based on seven periodic patterns [peak-to-peak amplitude (A): 20-40 mm, breathing period (T): 2-5 s] and 15 patients' aperiodic respiratory patterns (A: 6.5-22.9 mm, T: 1.9-5.8 s). The target position was detected in real time with the orthogonal kV x-ray imaging subsystem using the stereo vision technique. Subsequently, the Vero4DRT predicted the next position of the target, and then the gimbaled MV x-ray head tracked the corresponding orientation of the target. The displacements of the target were measured synchronously using the laser displacement gauge. The difference between the target positions predicted by the Vero4DRT and those measured by the laser displacement gauge was computed as the prediction error (E(P)), and the difference between the target positions tracked by the gimbaled MV x-ray head and predicted target positions was computed as the mechanical error (E(M)). Total tracking system error (E(T)) was defined as the difference between the tracked and measured target positions.

RESULTS

The root mean squares (RMSs) of E(P), E(M), and E(T) were up to 0.8, 0.3, and 0.7 mm, respectively, for the periodic patterns. Regarding the aperiodic patterns, the median RMSs of E(P), E(M), and E(T) were 1.2 (range, 0.9-1.8) mm, 0.1 (range, 0.1-0.5) mm, and 1.2 (range, 0.9-1.8) mm, respectively. From the results of principal component analysis, tracking efficiency, defined as the ratio of twice the RMS of E(T) to A, was improved for patients with high respiratory function (R = 0.91; p < 0.01).

CONCLUSIONS

The present study demonstrated that the Vero4DRT is capable of high-accuracy x-ray-image-based DTT. E(T) was caused primarily by E(P), and E(M) was negligible. Furthermore, principal component analysis showed that tracking efficiency could be improved with this system, especially for patients with high respiratory function.